Jul 9 – 13, 2018
Sofia, Bulgaria
Europe/Sofia timezone

Floating-point profiling of ACTS using Verrou

Jul 10, 2018, 3:45 PM
Hall 3 (National Palace of Culture)

Hall 3

National Palace of Culture

presentation Track 5 – Software development T5 - Software development


Hadrien Benjamin Grasland (Université Paris-Saclay (FR)) Bruno Lathuilière


Numerical stability is not only critical to the correctness of scientific computations, but also has a direct impact on their software efficiency as it affects the convergence of iterative methods and the available choices of floating-point precision.

Verrou is a Valgrind-based tool which challenges the stability of floating-point code by injecting random rounding errors in computations (a restricted form of Monte Carlo Arithmetic). Through bisection techniques, this tool is able to locate which parts of a codebase are correlated with significant losses of numerical accuracy.

The ACTS project aims to establish a experiment-agnostic track reconstruction toolkit. It originates from the ATLAS Run2 tracking software and has already received strong adoption by FCC-hh, and is being evaluated for possible use by the CLICdp and Belle 2 experiments.

We have used Verrou to evaluate the numerical stability of ACTS' Runge-Kutta track propagation. As this step is known to be a reconstruction bottleneck for many experiments, we expect significant performance gains to be achievable by introducing reduced-precision arithmetic in it. In this talk, we will present the results of this study and discuss the more general applicability of Monte Carlo arithmetic to High Energy Physics software.

Primary authors

David Chamont (LAL) Hadrien Benjamin Grasland (Université Paris-Saclay (FR))


Presentation materials